I had a young man named Tom come to my door the other night. He was so sweet and interesting; we even spent extra time on my porch talking about various things with him. I bought the Explore & Learn series and my mother bought the Advantage Math books. I have seen people write bad reviews, but instead I made my choice based on the product I saw and the individual I met. I am confident in my choice. I hope that young man reaches his life goals. All the best.